Swing-frame grinder



Aug. 13, 1929. STRATTON 1,724,115

SWING FRAME GRINDER Filed Dec. 19, 1927 S Sheets-Sheet 1 IN VEN TOR.

fizz-1157216327 BY m A TTORNEYS.

Aug 3, 1929. F. E. STRATTON 1,724,115

SWING FRAME GRINDER Filed Dec. 19, 1927 s Sheets-Sheet 2 1 llgr; g

ATTORNEYS.

Aug. 13, 1929. F. E. STRATTON 1,724,115

SWING FRAME GRINDER Filed Dec. 19, 1927 3 Sheets-Sheet 5 INVEN TOR.

ATTORNEYS.

Patented Aug. 13, 1929.

UNITED STATES PATENT OFFICE.

FRANK E. STRAT'ION, F EDGEWOOD, RHODE ISLAND, ASSIG-NOR TO DIAMOND MACHINE COMPANY, OF PROVIDENCE, RHODE ISLAND, A CORPORATION OF RHODE ISLAND.

SWING-FRAME GRINDER.

Application filed December 19, 1927.

My invention relates to swing frame grinders.

In swing frame grinders it is well known that the speed at which the grinding wheel thereof may be driven must have an upper limit for if the wheel is driven beyond this limit the centrifugal force of the rotating wheel will be greater than the binding action of the adhesive employed to join the abrasive grains thereof together, thereby causing the wheel to explode and fall to pieces.

So far as I am aware however, no one has hitherto discovered that as the diameter of the wheel wears down in use its tendency to fall to pieces is substantially diminished in proportion and that as the wheel wears down in use the peripheral speed may be increased,

thereby clearly increasing the elliciency of the grinding without any danger to the 0 workmen. I believe therefore, that I am the first to provide a swing frame grinder in which the peripheral speed of the grinding wheel may be increased with safety as the grinding wheel wears down in use and my invention broadly consists in providing in a swing frame-grindeig means to increase the peripheral speed of the grinding wheel as the grinding wheel wears down in use and broadly speaking it is immaterial whether this means is mechanical as shown in one type in the drawings or hydraulic as shown in another type in the drawings, or otherwise. Specifically applying my principle to a swing frame grinder I locate the wheel on one end of the fulcrum of the swing frame grinder and the driving means therefor on the opposite end thereof and the speed changing means in any desired location thereon, said speed changing means preferably being controlled by a manually operated movable member preferably located ad jacent the usual operating handle of the swing frame grinder.

I also realize that even though the wheel does wear down in use there constantly remains an upper limit of peripheral speed atwhich the wheel must not be driven in order to operate with safety and I therefore provide in combination with the'speed changing means hitherto referred to, means adapted to contact said wheel to prevent movement of said speed changing means to increase the driven peripheral speed of said wheel until the wheel has worn down preferably predegear box.

, preferred specific construction of the locking Serial No. 241,152.

termined amounts in use. It is thus apparent that although any type of speed changing may be employed, my preferred type of speed changing means consists of a mechanical change speed gear and I have especially designed a mechanical change speed gear which will operate in a straight line, to. render this type of mechanism practical on a swing frame grinder.

I also show in the drawings a hydraulically controlled and operated swing frame grinder which for purposes of operation on a swing frame grinder is also preferably constructed to operate in a straight line.

A further feature of my invention consists of means to lock the change speed mechanism thereof at any desired predetermined position. thereby preventing an unskilled operative from causing danger to himself and other workmen by tampering with my safety adjustment for the peripheral speed of the wheel. Further objects of my invention relate to a design of swing frame grinders in which the aforementioned features may be incorporated so constructed as to add a relatively small amount of weight to the swing frame grinder, a minimum number of part-s with the added parts so distributed that they in no way affect-the ready manipulation of the swing frame grinder.

Ihese and such other objects of my inven- -tion as may hereinafter appear will be best understood from a description of the accompanying drawings which illustrate various embodiments thereof.

In the drawings, Fig. l is a plan view of my preferred embodiment of a swing frame grinder in which the speed changing mechanism consists of a straight line shift gear- Fig. 2 is aside elevation thereof.

Fig. 3 is a longitudinal sectional View of the operating end of the swing frame grinder shown in Figs. 1 and 2 taken through the Fig. 4 is' a sectional viewt'aken along the line 44 of Fig. 3. I

Fig. 5 is a detailed sectional view taken along the line 5-5 of Fig. 4 showing the or v) mechanisnn 1 Fig. 6 is a plan View of a modified form of swing frame grinder employing a hydraulic drive into. which the speed changing and safety features of my invention are incorporated.

Fig. 7 is a side elevation of the embodiment of my invention shown in Fig. 6.

In the drawings, wherein like characters of reference indicate like parts throughout,

10 generally indicates a swmg frame grinder constructed in accordance with my invention, the swing frame grinder normally including the support 12 suitably mounted as usual above a frame 14, suitable means 16 to fulcrum said frame on said support, a grinding wheel 18 mounted on said frame 14 on one side of said fulcruming means 16, a motor 20 to drive said wheel mounted on said frame 14 on the opposite side'ofsaid fulcru'ming means 16, driving mechanism for said wheel 18 actuated by said motor and an operating handle 22 attached to said frame adjacent said wheel 18. I therefore incorporate into a standard type of swing frame grinder as just described, means to increase the driven' speed of the wheel 18 ,as the wheel wears down in use which means preferably includes a manually operated movable member 24. WVhile the means to increase the driven speed of the wheel as the wheel wears down in use may consist of any suitable. type of mechanical, hydraulic or other means for this purpose, said means preferably includes as shown in Figs. 15 the mechanical change speed gearing 26 suitably contained within the gear box 28 preferably located between the fulcrumin means 16 and the rinding wheel 18, pre erably inter osedin t e driving mechanism for said w eel. In thepreferred embodiment of my invention shown in Figs. 1-5, I preferably employ the change speed gearing 26 and means to shift said change speed gearing to increase the driven speed of said wheel as the'wheel wears down in use.

, As is customary in swing frame grinders, the rinding wheel 18 is suitably mounted on t e cross shaft 30 in suitable bearings 32 on the end of the frame adjacent the operating handle 22. The grinding wheel cross shaft 30 is driven by the drive shaft 34 preferably suitably contained within the frame 14 and which is normally provided at its end adjacent the cross shaft 30 with the bevel gear 36 adapted to drive the bevel gear 38 on said cross shaft 30. Said main drive shaft 34is driven as usual by the motor 20. I thus break the normal drive shaft 34 and interpose at the end thereofnormally driving the shaft 30 the change speed gearing 26. I thus in my preferred embodiment terminate the main drive shaft at the inner end of the gear box 28 and provide it at its broken outer end with the driving gear 40 I then provide the supplemental drive shaft 42 mounted in said gear box 28, the outer end thereof being suitably mounted from the inner to the in, the bearing 44 at the outer end of the gear box and the inner end thereof being suitably mounted or contained within a hole 46 cut centrally of the main drive shaft 34 so as to permit the supplemental drive shaft to be mounted substantially in line with the main drive shaft 34. Thus in my preferred embodiment I provide the outer end of the supplemental drive shaft with suitable means such as the bevel gear 36 to co-operate with suitable means, such as the bevel gear 38 to drive the grinding wheel cross shaft 30 and hence grinding wheel 18. I also mount the gear shaft 48 in said gear box 28 parallel to and adjacent to said aligned main drive shaft 34 and supplemntal drive shaft 42. Said gear shaft 48 is provided with the gear 50 on the inner end thereof adapted to intermesh and be driven by the gear 40 on the outer end of said main drive shaft 34. Said gear shaft 48 is provided with a plurality of change speed gears 52, 52", and 52 as shown decreasing in diameter from the inner gear 52 to the outer gear 52 outer end of said gear box 28. I also provide the sleeve shaft 54 of lesser length than said supplemental drive shaft. Said sleeve shaft 54 is provided with the square hole 56 adapted to receive the co-operating square supplemental drive shaft 42 so that when the sleeve shaft 54 is rotated, the supplemental drive shaft 42 will be driven thereby to drive the cross shaft 30 and hence the grinding wheel 18. The sleeve shaft 54 is preferably rovided with the clutch teeth 60 adapted when the sleeve shaft 54 is moved to innermost position to contact the circular clutch teeth 62 on the outer end of the main drive shaft 34 to drive said sleeve shaft 54 at its maximum speed. The sleeve shaft 54 is provided with the change speed gears 64, 64 and 64 increasing respectively in diameter from the inner to outer end thereof and adapted to respectively enmesh the change speed gears 52 52 and 52 respectivel on the gear shaft 48. Said s ee-ve shaft 54 is provided with suitable means, whereby it may be moved inwards to its innermost position in the gear box 28 to cause the gear 60 on the inner end thereof to enmesh the gear 62 on the outer end of the main drive shaft 34 thereby causing the grinding wheel 18 to be driven at its highest speed. The gears 64 64 and 64 are so spaced on the supplemental sleeve shaft 54 that in outermost position the gear 52 will contact the res ectively larger gear 64 to drive the supp emental drive shaft 42 at its lowest speed; when the sleeve shaft 54 is moved inwards, the relatively smaller ear 64 will be in mesh with the relatively arger gear 52 to cause the supplemental drive shaft to be driven at a greater speed;

and when the sleeve shaft 54 is moved further inwards, the relatively smaller gear 64 thereon will be in mesh With the relatively larger gear 52 on the inner end of said gear shaft 48 to cause the wheel 18 to be driven at a greater speed.

In my preferred embodiment in order to provide means to shift the change speed gearing, I provide the manually operated movable member 24 preferably located adjacent or near to the operating handle 22 preferably connected to the sleeve shaft 54 by the bifurcated arm 66 depending therefrom adapted to register in the annular groove 68 formed by the annular lips 70 on the outer surface of the slidable shaft 54 to move the sleeve shaft 54 to the relative positions mentioned hitherto. Interposed between the movable member 24 and the depending arm 66, I preferably locate the pad lock 72 which provides a suitable type of means to lock said operating handle when the relative change speed gears 52 and 64 are in the desired intermeshing positions.

In the embodiment of my invention shown in Figs. 6 and 7, I provide a hydraulic system as the driving mechanism for said Wheel specifically modified so as to include specific means to increase the driven speed of the Wheel 18 as the wheel wears down in use. In this embodiment, the means 20 to drive said wheel consists of the electric motor and the hydraulic pump 82; the driving mechanism for said wheel includes the hydraulic motor 84 located near the operating handle end 22 of the swing frame grinder 10 on the opposite side of the fulcruming.

means 16 from the hydraulic pump 82 and the pipes 86 suitably connecting said-hydraulic pump 82 with said hydraulic motor, which through suitable mechanism revolves the grinding wheel cross shaft 30. Thusin practice the electric motor 80 drives the wheel of the hydraulic pump 82 located on substantially the same main drive shaft 83 therewith and the liquid from the hydraulic pump 82 is circulated through the pipes 86 to revolve the hydraulic motor 84 which is mounted on the cross shaft 30 on which the grinding wheel 18 is mounted. In this embodiment the means to change the driven speed of the grinding wheel 18 consists of means to increase the stroke of the hydraulic pump 82 to increase the amount of fluid transmitted through the pipes 86 and forced against the blades of the hydraulic motor 84.

Any suitable type of hydraulic motor 84 may be employed and generally the hydraulic motor 84 is of the same type as the hydraulic pump 82. As it is necessary, however, to change'the stroke of the hydraulic pump 82, this preferably consists of a'pump in which the driving axis may be moved off center to vary the stroke thereof to vary the amount of fluid transmitted thereby. A

suit'able type of pump for this purpose is manufactured by the Oil Gear Company of Milwaukee, Wisconsin, and another suitable type of pump which may be employed is that described in Patents Nos. 1,152,729, 1,077,979, and 1,152,579 to Hole-Shaw in which the pump fulcrum is shifted by propor regulation of a pilot valve. The aforementioned patents are hereby referred to for further details of this pump. As shown in Figs. 6 and 7 the shaft 87 controls the pilot valve which changes the pump fulcrum to vary the stroke thereof to vary the amount of fluid transmitted through the con' necting pipes 86 to vary the speed of the hydraulic motor 84 which as explained drives the grinding wheel 18. The means to change the speed changing means, which in this instance comprises the hydraulic pump 82 instead of the change speed gearing 26 includes a manually operated movable element 24 adjacent the operating handle 22 connected by means of the arm 90, bell crank lever 92 and link 94 and lever 96 respectively to the shaft 87 which increases the stroke of .the pump in a manner as explained to in crease the speed of the hydraulic motor and hence grinding wheel as the wheel wears down in use. j

As stated hitherto, I preferably employ means adapted to contact said grinding wheel 18 and connected to said speed changing means, Whether said speed changing means comprises the change speed gearing 2G or the hydraulic pump 82, etc., to prevent shifting of the said speed changing means toincrease the driven speed of said wheel until said wheel is worn down predetermined amounts in use. In either embodiment of my invention, said means is generically the same and comprises a lever 100 suitably pivoted as at 102 having one arm 104 thereof adapted to continuously contact said rotating wheel 18 and having the other arm 106 thereof connected to said operating handle 24 in any suitable fashion, such as by the rod 108 so that the operating handle can not be moved to shift the speed changing means 26 to increase the driven speed of the grinding wheel until the wheel 18 wears down in use a predetermined amount. From an inspection of drawings, it is thus obvious that the operating handle 24 can only be moved further inwards in so far as the end 104 of the lever 100 may be moved inwards against the decreasing perimeter of the grinding wheel, thereby providing the 120 safety factor'heretofore described. In the embodiment shown in Figs. 6 and 7, the means to lock the speed changing means in any desired predetermined position in;-

eludes the threaded clamp 109 adapted to 125.

contact the arm 90 to clamp the arm 90 in any desired predetermined'position.

It isthus apparent that I have provided a swing frame grinder designed specifically to take into consideration, the normal reqfulcruming means,

uisites of a swing frame grinder, namely those of equalizing the balance, keeping down the weight, etc., into which has been incorporated a means to increase the peripheral speed of the grinding wheel for greater efliciency as the grinding wheel wears down in use and also safety means to prevent said increase above a safety limit until the wheel is Worn down in use a predetermined amount.

It is understood that my invention is not limited to the specific embodiments shown and that various deviations may be made therefrom withoutideparting from the spirit and scope of the appended claims.

What I claim is:

1. In a swing framegrinder a support, a frame, means to fulcrum said frame on said support, a grinding wheel mounted on said frame on one side of said fulcruming means, a motor to drive said wheel mounted on said frame on the opposite side of said fulcruming-means, driving mechanism for said wheel actuated by said motor, an operating handle attached to said frame adjacent said wheel, speed changing means interposed insaid driving mechanism, means including a manually operated movable member adjacent the operating handle to shift said speed changing means to increase 'the driven speed of said wheel as said wheel wears down in use, means to lock said speed changing means at set predetermined positions thereof and means adapted to contact said wheel and connected to said speed changing means to prevent movement of said speed changing means to increase the driven speed of said wheel until the wheel has worn downpredetermined amounts in use.

2. In a swing frame grinder, a support, a frame, means to fulcrum said frame on said support, a grinding wheel mounted on said frame on one side of said fulcruming means, a motor to drive said wheel mounted on said frame on the opposite side of said driving mechanism for said wheel actuated by said motor, an operating handle attached to said frame adjacent said wheel,- speed changing means interposed in said driving mechanism, means including a manually operated movable member to shift said speed changing means to increase the driven speed of said wheel as termined positions said'wheel wears down in use, means to lock said speed changing means at set predethereof and means adapted to contact said wheel and connected to said speed changing means to prevent movement of said speed changing means to increase the driven speed of said wheel until the wheel has worn down predetermined amounts in use.

3. In a swing frame grinder, a support, a frame, means to fulcrum said frame on said support, a grinding wheel mounted on said frame on one side of said fulcruming means, a motor to drive said wheel mounted on said frame on the opposite side of said fulcruming means, driving mechanism for said wheel actuated by said motor, an operating handle attached to said frame adjacent said wheel, a straight line advance change speed gearing interposed in said driving mechanism and means including a manually operative movable member adjacent the operating handle to advance said change speed gearing to increase the driven speed of the wheel as the wheel wears down in use and means adapted to contact said wheel and connected to said change speed gearing to prevent advancement thereof to increase the driven speed of the wheel until the wheel has worn down predetermined amounts inv use.

4. In a swing frame grinder, a support, a frame, means to fulcrum said frame on said support, a grinding wheel mounted on said frame on one side of said fulcruming means, a motor to drive said wheel mounted on saidframe on the opposite side of said fulcruming means, driving mechanism for said wheel actuated by said motor, an operating handle attached to said frame adjacent said Wheel, a change speed gearing 1nterposed in said driving mechanism and means including a manually operative movable member adjacent the operating handle to move said change speed gearing to increase the driven speed of the wheel as the wheel wears down in use and means adapted to contact said wheel and connected to said change speed gearing to prevent movement thereof torincrease the driven speed of the wheel until the wheel has worn down predetermined amounts in use.

In testimony whereof I aflix my signature.

FRANK E. STRATTON. 

